Socket Mobile Secure Digital Scan Card Series 3 - Manual (Page 35)

Appendix B
Bar Code Label Specifications
All bar code symbols/labels should satisfy the appropriate AIM
Uniform Symbology Specification.
Background Substrate:
The bar code symbol should be printed on material (media) that
is reflective and has a matte (not glossy) finish. A background
diffuse reflectance of at least 70% to 80% is desirable for
optimum contrast. Retro-reflective media should be used to
obtain decode distances greater than 36 inches.
Ink Color and Type:
The inked bars should not exceed 25% reflectance at the
wavelength that is being used for reading, whether printed with
black ink or colored ink. The reflectance value should not vary
more than 5% within the same character.
Voids and Specks:
The code should be printed clearly, free of voids, specks,
blemishes and lines that could “fool” the scanner. Specks or
blemishes in the white spaces, or false or missing bar sections
could be interpreted by the reading equipment as part of the
code. Generally, the width of such flaws is more serious than the
height. Code symbols/ labels should be rejected if these defects
are present.
Definition:
The bars in the bar code symbol should be well defined. Their
edges should not be rough or fuzzy, so that the bars and spaces
have the proper widths intended for the bar code symbology
used.
Contrast:
Background reflectance (that of the substrate on which the codes
are printed) should always provide a good contrast relative to
the ink reflectance (that of the code bars). The difference
between the two should be at least 37.5% at the wavelength
used for reading.
APPENDIX B: BAR CODE LABEL SPECIFICATIONS | 35